package com.bite.lesson1;

import java.util.Scanner;

public class Demo_02 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int ret = 0;
        while(scanner.hasNextInt()) {
            ret = scanner.nextInt();
            if(!fun(ret)) System.out.println("不是......");
            if(fun(ret)) System.out.println("是......");
        }

    }

    public static boolean fun(int ret) {
        for (int i = 2; i <= ret / 2; i++) {
            if (ret % i == 0) {
                return false;
            }
        }

        return true;
    }
}
